Production and characterization of monoclonal antibodies against recombinant human tumor necrosis factor/cachectin.

Tumor necrosis factor is a monokine, which causes cytolysis of many transformed cells. In this study we have found that in addition to cytotoxicity recombinant Escherichia coli-derived human tumor necrosis factor, like cachectin, inhibited the lipoprotein lipase of 3T3-L1 preadipocytes. Both effects were inhibited by monoclonal anti-tumor necrosis factor antibodies. Monoclonal antibodies against recombinant human tumor necrosis factor were produced by fusing splenocytes of immune mice with P3X63Ag8 653 myeloma cells. The monoclonal antibodies, namely BG 2-4, were of IgG2a, IgG, and IgG2a subclasses. These monoclonal antibodies neutralized the cytotoxicity of natural and recombinant human tumor necrosis factor but not that of rabbit or mouse tumor necrosis factor. They also neutralized the cachectin activity of human tumor necrosis factor in the 3T3-L1 embryonic cell assay. These results indicate that the functional structure(s) of human tumor necrosis factor responsible for the cytotoxicity and cachectin activities are likely to be closely related.